SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '174a4d97709612dbd993c5cd79b0e56feaef15879cdc5a153085c508b54ce2ff' 
  AND token = 'C25aDvkSfmc9i5nNe6byIRxQ4RrEMCbZ2te1MLQ8Ads=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}